The related art discloses a driving assist device that recognizes an object in the vicinity of a moving body such as a vehicle, a ship, or an airplane, and assists a driver in driving the moving body. There exist various fixed objects in the vicinity of the moving body. The fixed object can be divided into a non-obstacle that is not an obstacle to the movement of the moving body, and an obstacle to the movement of the moving body. For this reason, it is important to properly recognize a non-obstacle and an obstacle.
However, in practice, the vehicle as an example of the moving body may recognize a non-obstacle, for example, a manhole or a reflective plate as being an obstacle. For this reason, Japanese Unexamined Patent Application Publication No. 2011-18214 discloses a technology by which a non-obstacle is recognized as being a non-obstacle based on moving information of a preceding vehicle. However, according to this technology, it is not possible to recognize a non-obstacle as being a non-obstacle at all in a situation where there exist no preceding vehicles. As a result, a non-obstacle may be recognized as being an obstacle, and thus drive assistance may be given to cause discomfort to an occupant.
In addition, it may not be possible to recognize an obstacle such as a crossing gate, a metallic net, or a wooden fence, which does not sufficiently reflect a detective wave for detecting an object, as being an obstacle. As a result, it is not possible to recognize an obstacle as being an obstacle, and thus drive assistance may be given to cause discomfort to an occupant.